The present invention generally relates to a system and method for scanning and reading bar codes. In particular the present invention relates to a low-cost, one-dimensional scanner and reader which may be economically implemented on a PC card or hand-held scanner.
Bar code scanning and reading devices provide one of the great technological innovations of modern times. From quick check-outs in the grocery store to accurate inventory control for businesses, scanners/readers provide almost instantaneous computer recognition and documentation of various items while greatly relieving humans of mundane tasks thereby saving time and effort. Bar codes are typically vertical black and white bars that are scanned in a sequential fashion. In order for a computer to interpret a bar code, a scanner generally illuminates the bar code with a beam of light in a sequential, straitline fashion, while at the same time, a reader detects whether or not a region of a bar code is black or white. Depending on the order and spacing of the vertical black and white bars, a unique number pattern may be determined for a particular item. In most cases, the bar code scanners and readers have been combined to form one integral device to perform bar code scanning and reading simultaneously. Many styles for these devices include: hand-held gun style devices; wand-like devices; pen-like devices; and stationarily mounted devices in factories for example. In fact, a vast array of styles, shapes, and sizes of devices exist to provide for many diverse bar code applications.
Over the years, fairly complicated and elaborate mechanisms have evolved to scan bar codes. In order to produce a straitline, sequential scan pattern across the face of a bar code, many scanners employ rotating components to deflect a beam of light from one end of the bar code to another. In many conventional systems, the rotating components may be rotating mirrors that deflect a continuous light beam across the bar code as the mirror is rotated in front of the light beam. In other systems, the beam of light itself may be rotated while focusing the light directly on the bar code. Many times, motors and other electro-mechanical devices are employed to provide rotate the mirrors and/or lights. Unfortunately, mechanical components such as motors and rotating mirrors tend to wear over time which may ultimately produce mechanical failures in the scanners.
Other techniques have evolved which employ electronic systems to cause a light beam to move across a bar code. While solving some of the aforementioned problems with moving mechanical components, many of these electronic systems are fabricated by employing elaborate processes and materials. Also, many conventional electronic systems employ complicated geometrical shapes and structures to achieve desired scanning results.
Consequently, there is a strong need in the art for a non-mechanical system and/or method for bar code scanning that requires minimal components and fewer manufacturing processing steps which will ultimately provide more reliable and lower cost bar code scanners to consumers.
The present invention provides a low cost one-dimensional scanning and detecting system for reading bar codes and other related symbols. The system employs an electronic scanning and detecting system which may be implemented on a small printed circuit board such as a PCMCIA card or in a hand-held scanning and detecting system. In a PCMCIA card implementation, the bar code may be analyzed and digitized locally on the PCMCIA card before being sent over a PCMCIA bus to a hand-held or standalone personal computer (PC). Alternatively, the PCMCIA card may convert the analog bar code information and send the information to the PC for appropriate computer analysis and storage. Also, since electronic scanning and receiving systems are employed, the scanning and receiving systems may be applied to small, self-contained, hand-held applications such as may be seen in a check out line for example.
More particularly, the present invention employs a piezoelectric material that is uniquely shaped to provide a non-mechanical, low cost scanning system. In particular, the present invention geometrically exploits a radially-arced piezoelectric structure that allows for a small, discrete printed circuit board implementation of a one-dimensional bar code scanning and reading system. This allows, as discussed above, for a PCMCIA card implementation which provides bar code scanning in a hand-held computer application. The present invention may be implemented with lower component and manufacturing costs than conventional systems.
According to one particular aspect of the present invention, a system is provided for scanning a target. The system includes a light source for directing a beam of light to a radially-arced piezoelectric material having a reflective surface for receiving at least a portion of the beam of light. The reflective surface directs at least a portion of the beam of light to the target, and a power source provides movement in the radially-arced piezoelectric material to scan at least a portion of the beam of light across at least a portion of the target. The at least a portion of the target is reflected onto a photosensor to provide an electrical signal representing the reflected light.
According to another aspect of the present invention, a system is provided for scanning and reading a target. The system includes: a means for directing a beam of light; a means for reflecting at least a portion of the beam of light to the target; a means for providing movement in a radially-arced piezoelectric material to change the shape of the reflecting means which effects scanning of at least a portion of the beam of light across at least a portion of the target; and a means for providing an electrical signal representing the reflected light.
According to still yet another aspect of the present invention, a method is provided for scanning and reading a target. The method includes: directing a beam of light to a radially-arced piezoelectric material having a reflective surface; receiving at the target at least a portion of the beam of light from the reflective surface; applying at least one predetermined voltage to the radially-arced piezoelectric material so as to cause the reflective surface to change shape which results in scanning of at least a portion of the beam of light along the target; and receiving at a sensor at least a portion of the beam of light from the target to provide an electrical signal representing the received light.
According to still yet another aspect of the present invention, a system is provided for scanning and reading a target. The system includes: a system for directing a beam of light; a system for providing movement in a radially-arced piezoelectric material having a reflective surface which effects scanning of at least a portion of the beam of light across at least a portion of the target; and a system for providing an electrical signal representing the reflected light.
According to still yet another aspect of the present invention, a system is provided for scanning and reading a target. The system includes: a light source for directing a beam of light; a piezoelectric material affixed to a radially-arced reflective surface for receiving at least a portion of the beam of light; wherein, the reflective surface directs at least a portion of the beam of light to the target; an AC voltage source for selectively applying predetermined voltages to the piezoelectric material so as to cause the radially-arced reflective surface to change shape which results in scanning at least a portion of the beam of light across at least a portion of the target; wherein, at least a portion of the beam of light reflected from at least a portion of the target is reflected onto a photosensor to provide an electrical signal representing the reflected light.
According to still yet another aspect of the present invention, a PCMCIA card is provided for scanning a bar code. The PCMCIA card includes: a light source for directing a beam of light; a radially-arced piezoelectric material having a reflective surface for receiving at least a portion of the beam of light; wherein, the reflective surface directs at least a portion of the beam of light to the bar code; a voltage source for selectively applying predetermined voltages to the piezoelectric material so as to cause the radially-arced reflective surface to change shape which results in scanning at least a portion of the beam of light across at least a portion of the target; wherein, the bar code reflects at least a portion of the beam of light to a photo sensor to provide an electrical signal representing the reflected light; and a conversion and interface system for transmitting a digital representation of the electrical signal across a PCMCIA bus to a scanner processing system to interpret the bar code.
To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described. The following description and the annexed drawings set forth in detail certain illustrative embodiments of the invention. These embodiments are indicative, however, of but a few of the various ways in which the principles of the invention may be employed. Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the drawings.